One crank, one drop, one minute: a blood test that needs no electricity

When someone is badly hurt, two numbers matter fast: their blood type, so a transfusion is safe, and their hematocrit — the share of their blood made of red cells, which reveals blood loss or anaemia. Hospitals measure both with big machines that need power and trained staff, neither of which exists in an ambulance, a disaster zone or a remote clinic. Professor Chien-Fu Chen's team at National Taiwan University has built the alternative: a small plastic chip spun by a hand-cranked centrifuge, using about 3 microlitres of blood from a finger prick. Red bands on the chip show the A, B and Rh blood groups at a glance, and the band's length gives the hematocrit. In tests on 21 hospital patient samples, published in Biosensors and Bioelectronics, the readings closely matched standard hospital analysers — and the whole test takes about one minute.

SDG 3 · Good health and well-being — Mechanism: tech innovation